US 4,689,979 A · Pressing method and punch and die press for the same

Abstract

A method of pressing a blank comprises the steps of pressing the blank between a die assembly having a cavity with a highly viscous substance contained therein and a punch, inserting the punch into the cavity to increase a pressure of the highly viscous substance in the cavity, and pressing the blank against a surface of the punch under the pressure of the highly viscous substance. The pressing method can form pressed product of complex shape highly accurately and free from cracks, wrinkles, or other damages. There is also disclosed a punch and die press suitable for effecting the abovesaid pressing method.

Claims14

Dependent claims

A method of pressing a blank, comprising the steps of:

(a) pressing the blank between a die assembly having a cavity containing a highly viscous substance with dilatant and thixotropic properties therein, and a punch;
(b) inserting said punch into said cavity to increase a pressure of the highly viscous substance in said cavity;
and
(c) pressing said blank against a surface of said punch under said pressure of said highly viscous substance such that the pressure of said highly viscous substance does not reach a final pressing pressure until said punch closely approaches a final insertion depth on said cavity.

1 more element

Dependencies are inferred from the claim text.

Pressing method and punch and die press for the same

Life of this patent

Pressing method and punch and die press for the same

Life of this patent

Abstract

Claims14